Wound Occlusion Research Articles

The Effect of Preoperative Chlorhexidine Gluconate Cleanse on Lower Extremity Surgical Site Infections: A Retrospective Cohort Study.

Lower extremity surgical sites are at an increased risk of wound infection following Mohs micrographic surgery. To evaluate the rate of lower extremity surgical site infections following a 14-day regimen of preoperative 4% chlorhexidine gluconate (CHG) rinses and postoperative wound occlusion for 14 days. Retrospective data were collected from procedures performed by the senior author from January 2022 through June 2023. To meet inclusion, patients must have completed waist-down CHG soak and rinse for 14 days before surgery, including the day before surgery. In addition, the patient must have kept the dressing clean, dry, and intact until the postoperative appointment at 14 days. A total of 100 Mohs cases met inclusion criteria. Zero patients developed a surgical site infection. Chlorhexidine gluconate preoperative rinsing and postoperative occlusion for 14 days may minimize the risk of wound infection. Although further research is indicated, an opportunity exists for the adoption of CHG into routine clinical practice in the outpatient dermatology setting.

The Effects of Cellular Skin Substitutes on Diabetic Foot Ulcer Healing: A Systematic Review

Introduction: Diabetic foot ulcer (DFU) is one of the most common lower extremity diabetes-related complications. New therapies have been developed to increase the likelihood of wound healing and reduce complications, including biological and/or synthetic grafts that allow a temporary or permanent occlusion of wounds. Although their efficacy has been demonstrated, novel skin substitutes have been available, and few studies have described the head-to-head comparative effectiveness of those products. Therefore, this mini-review aims to analyze the available randomized clinical trials studying the impact of different cellular skin products on the healing of DFUs. Methods: The databases PubMed, EMBASE, Scopus, Scielo, and Lilacs were assessed from inception to July 30th, 2023, to identify randomized clinical trials on the effects of cellular skin substitutes on ulcer healing in adult patients aged 18 years or older with DFUs restricted to the skin and subcutaneous tissue, compared to standard of care or other skin substitutes. Results: Based on eligibility criteria, 22 articles were selected. These studies showed the efficacy and safety of cell skin substitutes compared to standard treatments, as demonstrated by the reduction in the total area of the ulcer and rates of complete wound healing. We identified a few studies with head-to-head comparisons among those products. Discussion: Cellular skin substitutes have shown promising results in healing DFUs as complementary therapies to the standard of care. Their incorporation into standard-of-care treatments could be discussed. Future studies should focus on head-to-head comparisons, cost-effective analysis, and long-term efficacy and safety.

A «Push&Plug» Lifesaving Device to Prevent Exsanguination

Introduction:Severe bleeding from external wounds is a major reason for death. Immediate control of hemorrhage is of highest priority. We present the novel Acute Wound Occluder (AWO) which was developed for rapid and targeted wound occlusion. Here, we present the design, in-vitro testing, and in-vivo performance compared to QuikClot® using a clinically-relevant pig model.Method:AWO is made of an applicator with pushing function into which a self-expanding, Silicone coated Nitinol meshgraft is mounted to enable plugging into the wound-channel. In-vitro tests included biocompatibility, cytotoxicity, skin sensitization, and aging validation. Next, 12 pigs underwent standardized sized femoral-artery puncture to mimic life-threatening bleeding and were either treated with the AWO (n=6) or QuikClot® (control). Animals were followed-up for 4hrs, before device-removal macroscopic assessment.Results:The AWO successfully passed all in-vitro tests. The AWO could be delivered within 40±15 seconds to the wound to achieve instant bleeding control, and no additional manual compression needed. Quick Clot application was less convenient, with approximately four minutes (application 56±8ss, plus three minutes of manual compression) to achieve bleeding control. In all AWO treated pigs, exsanguination could be prevented immediately, no major blood-pressure drops occurred, with four pigs where bleeding could be completely stopped, and two pigs with irrelevant oozing which stopped within 75-150 seconds leading to minimal blood-loss of 12ml and 2ml. Tissue-analysis showed only small hematomas in five out of six animals. In contrast, QuickClot treated pigs showed significant bleeding and a blood-loss of 19ml. All six pigs showed substantial hematomas, two out of six showed very large hematomas. AWO application appeared to be safe with no peri-procedural adverse-events (AEs) or collateral damage to surrounding tissues.Conclusion:The AWO enables rapid and targeted control of life-threatening bleeding without any AEs. The AWO may represent a promising hemostatic device for bullet or knife-stab wounds.

83 Wnt signaling attenuates mechanotransduction and protects against wound occlusion-mediated abolishment of regeneration

OBJECTIVES/GOALS: Current clinical practice recommends occlusive dressings (e.g., film and hydrocolloid) for wounds with variable regenerative capacities. However, clinical evidence suggests that occlusion may hinder regeneration. Our objective was to test the impact of occlusion on regeneration using animal models. METHODS/STUDY POPULATION: The murine wound-induced hair neogenesis (WIHN) is a well-established model of regeneration characterized by de novo hair follicle (HF) formation in the center of large full-thickness wounds. The quantity of neogenic HFs depends on the robustness of Wnt signaling. Optimal tissue mechanics is also required for WIHN. Utilizing the murine WIHN model, we tested the hypothesis that wound occlusion impedes regeneration. We determined how (i) the timing and duration of wound occlusion impacts WIHN, (ii) Wnt signaling influences the occlusion-induced effects on regeneration and (iii) occlusion alters the tissue mechanics of the wound, which establishes the morphogenetic field needed for WIHN. RESULTS/ANTICIPATED RESULTS: Occlusion completely eliminated WIHN. Only a brief period of occlusion between post-wound days 0-3 or 4-7 was sufficient to abrogate WIHN. Microarray and qPCR of open and occluded wounds demonstrated that occlusion promotes fibrosis by upregulating TGF-β2 and mechanotransduction, a mechanosensitive profibrotic pathway. Recruitment of these potent profibrotic pathways generated a symmetrically rigid wound incapable of de novo HF regeneration. Using transgenic animal models with enhanced Wnt signaling, we determined that the ligand-dependent Wnt signaling protected against the occlusion-induced inhibition of WIHN, as well as the occlusion-induced upregulation of both profibrotic pathways. DISCUSSION/SIGNIFICANCE: In animal models, occlusion promoted fibrosis at the expense of regeneration during acute wound healing. Augmented Wnt signaling protected against this effect. Occluding wounds may reduce regeneration. Further studies are warranted to validate these findings.

The use of occlusive dressings: influence on excisional wound healing in animal model.

To analyze the influence of occlusive dressing on the healing of excisional skin wounds in mice. Pre-clinical, comparative, and translational study. Mice were divided into three experimental groups: wounds occluded with hydrocolloid (HD) dressings, transparent polyurethane film (TF) dressings, and without occlusion (WO), monitored at three, six and 14 days, with eight animals each. Closure rate, infiltration of neutrophils and macrophages, measurement of tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) and, histologically, angiogenesis were evaluated. Wound closure was accelerated in the occlusive groups. There was a decrease in TNF-α levels in the HD group when compared to the WO and TF groups. Neutrophils accumulation decreased in the HD group. Increased dosages of macrophages were evidenced in the HD group, compared to the WO and TF groups. Levels of VEGF were increased in the TF and HD groups. It is suggested that the occlusion of wounds modulates the inflammatory response.

Current aspects of the wound process treatment using dressings (bandages)

The review provides information concerning the assortment of modern wound dressings (bandages) which are presented on the pharmaceutical market. The studied group of dressings varies widely in chemical composition and active pharmaceutical ingredients. It has been determined that the development of modern wound dressings provides for the realization of a complex effect on the wound process, which is achieved by the multi-layer structure of the dressing (bandages) with clearly defined functions of each component – the contact layer reduces adhesion to the wound surface; sorption layer provides irreversible sorption, retention and inactivation of wound exudate; pharmacologically active layer influences the main factors of wound process pathogenesis; outer isolating membrane generates wound occlusion. Conclusions. The events of recent years which related to the Anti-terrorist operation / the Joint Forces Operation in Ukraine indicate the unresolved problem of combat surgical trauma treatment. This is an important issue for the Medical services of the Armed Forces and the health care system of Ukraine. This necessitates expanding the range of wound dressing (bandages) with combined action for military medicine. It has been determined that the treatment in the purulent-necrotic phase of the wound process, it is advisable to use wound dressings with strong osmotic and antibacterial activity and low adhesion to the wound surface. In the second phase of the wound process, it is advisable to use wound dressings with moderate osmotic activity and a combination of antibacterial and reparative properties. In the final phase of the wound process, wound dressings should prevent drying of the wound surface as well as protect and stimulate the growth of granulations.

An advanced decellularized dermis intended for soft tissue repair: A new surgical approach for DFU

Skin substitutes are heterogeneous group of biological and/or synthetic elements that enable the temporary or permanent occlusion of wounds. Although dermal substitutes can vary from skin xenografts or allografts to a combination of autologous keratinocytes over the dermal matrix, their common objective is to achieve the greatest possible similarity with the patient’s skin The acellular dermal matrix allows the body to rebuild its own strong tissue without the need for alloplastic material. The three-dimensional collagen will be replaced by vital new tissue. An alternative treatment for diabetic foot ulcers is a matrix scaffold for new tissue generation, an acellular human dermal matrix (ADM) allograft. Decellularized human skin has been used for a variety of medical procedures, primarily involving wound healing, soft tissue reconstruction, and sports medicine applications.

553 Treatment of Scalp Pressure Ulcers with an Aerosol Formula with Silver Sulfadiazine, Lidocaine and Vitamin A: Early Clinical Experience

Abstract Introduction Management of scalp pressure ulcers (SPU) in patients admitted to intensive care units (ICU) remains a challenge. The impossibility of freely moving the head due to different factors such as the intubation, enteral nutrition, dialysis and use of extracorporeal membrane oxygenation among others, makes the management of these wounds problematic. Herein, we present our early clinical experience in the treatment of SPU with a novel aerosol formulation of silver sulfadiazine. Methods A prospective study including all patients with SPU who were treated with an aerosol formula that includes silver sulfadiazine, lidocaine and vitamin A was carried out. Wound dressings were changed every 12h and consisted in wound cleansing, aerosol application and occlusion with sterile gauze. Evolution of each SPU was controlled with pictures and measures on the affected area every 48 hours. In order to determine the total wound area, pictures were analyzed using the Informatics Image System from the U.S National Institute of Health. Results Six patients were prospectively followed and were included in this study. There were 2 females and 4 males. Average age was 70.8 years (range 41–99), while average hospital stay in the ICU was 14 days (range 5–22). None of these patients experienced wound progression to a more critical stage. One patient had a favorable evolution from stage IV to stage II. Also, none of them showed clinical signs of a local infection of the SPU. The average quantity of aerosol used per dressing was 1.3 ml which represents 2,6 mm/day and a cost of A$106,16 (U$S 1,45). As the cost of hydrocolloid dressings, at our institution, is A$602 per dressing (U$S 8,24), this represented an important saving in costs. Conclusions In this case series, the use of this novel aerosol formulation of silver sulfadiazine has shown promising results in the treatment of SPU in patients admitted to ICU, facilitating the application and saving costs. Further and larger studies to confirm our encouraging preliminary results are warranted.

Multifunctional nanofibrous patches composed of nanocellulose and lysozyme nanofibers for cutaneous wound healing

Cutaneous wounds frequently require the use of patches to promote healing, nevertheless, most commercial products are fabricated with non-biodegradable synthetic substrates that pose environmental problems upon disposal. Herein, the partnership between two biobased nanofibrous polymers, namely a polysaccharide (nanofibrillated cellulose (NFC)) and a protein (lysozyme nanofibers (LNFs)), is explored to design sustainable fibrous patches with good mechanical performance and biological functionalities for wound healing applications. Two patches with different morphologies were prepared by vacuum filtration of a water-based suspension of both nanofibers and by sequential filtration of the separated suspensions (layered patch). The resultant freestanding patches exhibited high thermal stability (up to 250 °C), mechanical performance (Young's modulus ≥3.7 GPa), and UV-barrier properties. The combination of the bioactive LNFs with the mechanically robust NFC conveyed antioxidant activity (76–79% DPPH scavenging) and antimicrobial activity against Staphylococcus aureus (3.5–log CFU mL−1 reduction), which is a major benefit to prevent microbial wound infections. Moreover, these patches are biocompatible towards L929 fibroblast cells, and the in vitro wound healing assay evidenced a good migration capacity leading to an almost complete wound occlusion. Therefore, the partnership between the two naturally derived nanofibrous polymers represents a potential blueprint to engineer sustainable multifunctional patches for cutaneous wound healing.

Wound occlusion and annual stem growth rates of five woodland tree species in South Africa

Sustainable management strategies for trees are informed by research on growth rates and regeneration. In a 1998 study of bark thickness and tree size, six species (all used for traditional medicine) were sampled by removing 5 cm-diameter bark disks at four height intervals on 210 stems at 15 sites in South Africa. An impromptu revisit to one site in 2003 revealed that wounds for one species exhibited very little wound occlusion. These observations prompted a 2004 study on wound occlusion and stem growth for five of the species at six sites (Albizia adianthifolia, Balanites maughamii, Elaeodendron transvaalense, Searsia chirindensis, Warburgia salutaris), where 84 stems were re-measured. There were species-specific stem growth and wound occlusion rates. In general, annual lateral stem growth at 1.3 m was inversely related to stem size (corroborated by lateral widening responses of the original wound edges). There was also a tendency for smaller and/or faster growing stems to exhibit more wound occlusion and faster rates of bark regrowth – except in W. salutaris, where smaller individuals exhibited comparatively lower rates of occlusion compared to bigger individuals. All wound occlusion was by bark edge growth (typically <3 mm y−1); only A. adianthifolia showed complete wound closure, whereas B. maughamii showed the least (17%±19%). An inverse relationship existed between density (timber and bark) and stem growth, wound occlusion and lateral widening of the old scar edges – except for S. chirindensis. Hence trees with softer wood and bark generally grew quicker and exhibited more wound occlusion than trees with harder wood and bark.

Imaging of bacteria in burn wounds treated with split-thicknessgrafts in MEEK/MESH technique: a pilot study with first experiences in clinical wound evaluation with autofluorescence

Partial and full thickness burns require surgical treatment, such as early débridement and skin transplantation in MEEK/MESH technique or further reconstructive surgery. Infections of burns or transplanted areas limit surgical success and increase patient mortality. For split-thickness grafts in MEEK technique a superficial silk is applied as a protective on-top dressing, whereas in MESH technique fatty gauze and foam are used as standard protective covers over five to seven days. However, wound occlusion by both materials provides the soil for growth of microorganisms. The timely identification of impending infections is necessary to initiate early removal in order to safe and preserve skin grafts. Early identification of infections and removal of foreign material should therefore be attempted. Burn wounds treated with split-thickness skin grafts processed by MEEK/MESH technique and covered with silk or foam overlayers were analyzed for signs of bacterial infection using the MolecuLight i:X™ device. In addition, swaps for microbiological analysis where taken from fluorescent areas and correlated with florescent image results. We examined burn wounds (n = 14) of three different intensive care patients. The MolecuLight i:X™ camera showed a strong colonization of the transplanted areas and foreign materials, that were in line with microbiological analysis findings. The representation of the excitation load showed high values in the foreign materials. The take rate of MEEK-transplants was 90 % compared to MESH-transplanted with about 60 %. The positive predictive value was 81.8 % for detection of a wound infection with autofluorescence. The negative predictive value was 90.3 % with a sensitivity of 86.7 % and a specificity of 87.5 %. The representation of the fluorescence exciter load shows high concentrations of pathogens both in the MEEK silk layer as well as in foam linkers. Overall split-thickness grafts according to the MEEK technique showed a higher healing rate compared to MESH technique. Screening of burns wounds with autofluorescence imaging can be helpful for an additive wound assessment. Split-thickness graft covers should be applied only for a minimum time period required to ensure stable grafting.

Effect of pruning season and tool on knot occlusion and stem discolouration in &lt;i&gt;Betula pendula&lt;/i&gt; – situation five years after pruning

This paper investigates and models the effects of pruning season and tool on wound occlusion with varying tree and branch characteristics of silver birch (Betula pendula Roth) stems at the pruning height of 0−4 metres. Dates of eight secateurs prunings, three saw prunings and two sticks prunings as well as unpruned control were tested in permanent plots on four sites. Knot occlusion and discolouration in stemwood were measured from about 1600 studied knots of 112 sample trees felled five to six years after pruning in 2010. Knot occlusion rate was modelled according to pruning tool, date, tree growth, and branch characteristics. The occlusion was the fastest in trees pruned in spring or early summer, and the slowest in trees pruned in autumn. Stubs of living branches occluded faster than the dead ones with the same diameter. Saw pruning resulted in clearly better occlusion rates than secateurs pruning, caused by the shorter knot stubs after saw pruning. Hitting dead branches away with a stick resulted in the worst occlusion status. The colour defects spread more often upward from the knot than downward. Discolouration in stemwood was detected more frequently near to the pruned branches than the unpruned ones, and more widely near to the stubs of dead branches than the living ones. Most saw and secateurs pruned branches were completely occluded during the experiment, so these prunings were suitable for all branches under 20 mm in diameter, and for living branches even up to 30 mm in fast-growing trees.

Pruning effect on Norway spruce (Picea abies (L.) Karst.) growth and quality

Abstract Pruning requires significant investment, therefore, the aim of the study was to characterize occlusion of branch wounds and changes in radial increment as well as frequency of browsing damages after pruning of Norway spruce (Picea abies (L.) Karst.) in order to provide data for financial calculations and recommendations for practical forestry. Altogether 1,614 pruned and 4,368 unpruned trees from 45 Norway spruce stands were measured and cored. Degree of wound occlusion and browsing damages were assessed, and additional volume increment estimated in each stand. Pruning resulted in significant increase of length of branch-free section: for unpruned trees it was 0.3 ± 0.07 m, but for pruned 3.4 ± 0.10 m. Branch wounds for most of the trees (68%) were filled with resin (occluded), for lower share of trees (31%) – still open, but for some trees (1%) completely occluded. Branch wound occlusion rate was not affected by differences in stand density, but was significantly affected by stand age: proportion of trees with occluded branch scars increased with age. Trees with occluded branch wounds had a significantly higher increase in tree ring width after the pruning in comparison to the period before pruning than trees with open branch wounds, emphasizing the importance of radial increment in development of branch-free layer of wood. Pruning resulted in minor (−7% or −0.28 ± 0.05 m3 ha−1) reduction of annual increment that was statistically significant only up to 3 years after this forest management activity for stands younger than 17 years and with mean height up to 10.5 m. Pruned trees were significantly more browsed than unpruned (6.1% and 2.7%, respectively).

Development of stem cracks in young hybrid aspen plantations

Abstract Cracks expose wood to fungal infections that significantly affects wood quality, while rapid wound occlusion decreases probability of infections. Assessment of scars was done at four grade scale in three adjacent hybrid aspen trials at the age of 8-10 years in central part of Latvia three years after bark crack occurrence. Occluded wounds were found for 95% of damaged trees, regardless of tree age. Among trees that had cracks wider than 1 cm, 42% had uniformly healed bark, but 7% still had open wounds. Wound development was significantly affected by crack width and length (both p &lt; 0.001), but had no clear relation with tree DBH (diameter at breast height) and relative DBH increment (both p &gt; 0.05). At clonal mean level, scar grade was significantly affected by grade of crack three years earlier and clone (both p &lt; 0.001), but mean DBH of clone had no relation (p &gt; 0.05) to proportion of trees evaluated by any of the scar grades. The results suggest that three years after the bark crack formation most of them had successfully occluded and selection of clones with better diameter growth has no influence on development of cracks.

Factors affecting branch wound occlusion and associated decay following pruning – a case study with wild cherry (Prunus avium L.)

Pruning wild cherry ( Prunus avium L.) is a common silvicultural practice carried out to produce valuable timber at a veneer wood quality. Sub-optimal pruning treatments can permit un-occluded pruning wounds to develop devaluing decay. The aim of this study is to determine relevant branch, tree and pruning characteristics affecting the occlusion process of pruning wounds. Important factors influencing occlusion time for an optimised pruning treatment for valuable timber production utilising wild cherry are derived. 85 artificially pruned branches originating from ten wild cherry trees were retrospectively analysed. Branch stub length, branch diameter and radial stem increment during occlusion were found to be significant predictors for occlusion time. From the results it could be concluded that for the long term success of artificial pruning of wild cherry it is crucial to ( i ) keep branch stubs short (while avoiding damage to the branch collar), ( ii ) to enable the tree to maintain significant radial growth after pruning, ( iii ) to avoid large pruning wounds (>2.5 cm) by removing steeply angled and fast growing branches at an early stage.

Endovascular therapy with intravascular ultrasound guidance for popliteal artery occlusion due to blunt trauma

Abstract Background Historically, popliteal artery occlusion due to blunt trauma has led to high amputation rate and been thought that indication for traditional open operative repair in almost all of cases. Case A healthy male in his 30s transferred to the advanced wound care center at our hospital because unhealed wound and popliteal artery occlusion due to blunt trauma after traffic accident. Surgical repair was planned, but was postponed due to wound contamination. Endovascular therapy was selected and balloon angioplasty was performed with intravascular ultrasound (IVUS) guidance successfully. Thereafter wound management, wounds were successfully cured at 3 months after admission. Conclusion Popliteal artery occlusion due to blunt trauma resulted in lower leg necrosis and successful lower leg preservation was achieved by EVT with using IVUS

The chemistry and engineering of polymeric hydrogel adhesives for wound closure: a tutorial.

The closure and repair of wounds after traumatic or surgical injury is of significant clinical and research importance. While sutures remain the common wound closure technique, they have many disadvantages. Consequently, polymeric hydrogel adhesives have emerged as essential materials for wound management and repair because of their tunable chemical and physical properties, which enable them to adhere or stick to tissues, possess sufficient mechanical strength to stay intact and be subsequently removed, provide complete wound occlusion, and act as a barrier to bacterial infection. Moreover, these materials absorb wound exudates and keep the wound moist for faster healing. This tutorial review summarizes the key chemical features that enabled the development and use of polymeric hydrogels as wound adhesives, sealants, and hemostats, their design requirements, synthetic routes, determination of properties, and the tests needed to evaluate their performances. This tutorial review is a reference and a starting point for scientists and clinicians working or interested in the field of wound management and, importantly, for the general audience who is interested in polymers for medical applications.

Wound healing efficacy of a chitosan-based film-forming gel containing tyrothricin in various rat wound models

The objective of this study was to evaluate the healing effects of a chitosan-based, film-forming gel containing tyrothricin (TYR) in various rat wound models, including burn, abrasion, incision, and excision models. After solidification, the chitosan film layer successfully covered and protected a variety of wounds. Wound size was measured at predetermined timepoints after wound induction, and the effects of the film-forming gel were compared with negative (no treatment) and positive control groups (commercially available sodium fusidate ointment and TYR gel). In burn, abrasion and excision wound models, the film-forming gel enabled significantly better healing from 1 to 6 days after wound induction, compared with the negative control. Importantly, the film-forming gel also enabled significantly better healing compared with the positive control treatments. In the incision wound model, the breaking strength of wound strips from the group treated with the film-forming gel was significantly increased compared with both the negative and positive control groups. Histological studies revealed advanced granulation tissue formation and epithelialization in wounds treated with the film-forming gel. We hypothesize that the superior healing effects of the film-forming gel are due to wound occlusion, conferred by the chitosan film. Our data suggest that this film-forming gel may be useful in treating various wounds, including burn, abrasion, incision and excision wounds.

Occlusion of pruning wounds on northern red oak (Quercus rubra) trees in Romania

This study focuses on the occlusion of pruning wounds on northern red oak (Quercus rubra L.) trees grown in two plantations established in the south-east of Transylvania, Romania in 1997 and 2004. In total, 184 green branches of elliptical cross section (i.e. with the horizontal axis Ha shorter than vertical axis Va and ranging between 0.6 cm and 4.5 cm) were pruned in April 2007 and May 2009. Of these branches, 161 (88%) were fully occluded after five growing seasons and, the majority of these, 148 wounds (80%), had occluded in three seasons. The main factors affecting the wound occlusion on trees subject to artificial pruning are diameter at breast height increment and branch size: the occlusion is more rapid in trees with faster diameter growth rates and on small branches of maximum 3 cm Ha. Consequently, artificial pruning should be concentrated on small branches on well formed, vigorous and evenly spaced final crop trees which can subsequently be favoured by heavy and targeted thinning from above, allowing the production of large diameter, high-quality trees in 50–70 years.

The incorporation of Brazilian propolis into collagen-based dressing films improves dermal burn healing

Ethnopharmacological relevanceHydroalcoholic solutions of propolis, a resinous product produced by bees, have been currently employed in improving the cicatricial repair. Biological activity of propolis might be related to its antimicrobial, anti-inflammatory and immunomudalatory properties. Aim of this studyInvestigate the suitability of the collagen-based films containing hydroalcoholic extracts of two different varieties of Brazilian propolis (green and red ones) on the dermal burn healing in rodent model. Materials and methodsThe hydroalcoholic extracts of red propolis (RP) or Green propolis (GP) were incorporated into collagen-based dressing films (COL). Burn wounds were performed in the dorsum of Wistar rats and dressing with COL, COL+GPa (0.5%), COL+GPb (1,0%) or COL+RP (0.5%). A control group (CTR) was performed keeping the wound undressed. The histological analyses were carried out after 3, 7, 14, 21 and 30 days for histological assessment of the inflammatory response, epithelization rates (ER), myofibroblastic count (MC) and collagenization pattern. ResultsGPa, GPb and RP provided significant decrease of the inflammatory severity, improved the ER in GPa in 7 (p=0.000), 14 (p=0.000), 21 (p=0.005) and 30 days (p=0.015), and induced earlier replacement of type-III for type-I collagen (p<0.05) than COL and CTR. In all the groups, the MC increased progressively from 3 to 14 days, and then started to decrease slowly until 21 days. Although no significant difference was observed among the groups in 3, 7 and 30 days, the MC was significantly increased in RP in 14 (p=0.0001) and 21 days (p=0.04), as well as grosser interlacement of the collagen bundles compared with the other groups. ConclusionThe incorporation of hydroalcoholic extracts of Brazilian propolis improved the biological events associated to burn healing without toxic effects, but the red variety provided the best results. Therefore, these collagen-based containing natural apicultural products films may be considered a promising new dressing for wound occlusion and tissue repairing.